Amount Of Radioactive Material Research Articles

Radioactive Material Shipment Checklist

Health Physicists who do not regularly prepare shipments of Type-A quantities of radioactive material may be daunted by the applicable regulations. This article presents a checklist to help prepare shipments of Type-A quantities.

IAEA Transport Regulations—what has Changed in 40 years

AbstractThe IAEA Regulations for the Safe Transport of Radioactive Materials were first published in 1961. It was stated in the foreword of the first edition that the transport of increasing amounts of radioactive materials posed technical problems because of the hazards involved and it also stated that the procedures to be complied with should not be too complex and should apply to any mode of transport. The requirements for the packaging of radioactive materials for transport were expressed in terms of provisions and were described in general qualitative terms. Satisfying these requirements would provide safety for the transport of radioactive materials. Since 1961 the regulations have been revised on a number of occasions in order to add clarity and provide detail to the various requirements. These revisions have added a greater complexity to the provisions but the underlying principles used to provide for safe transport are still the fundamental bases for the regulations. This paper looks at some key ...

Issues in the Comparison of Risk Estimates for the Population in the Techa River Region and Atomic Bomb Survivors

Plutonium production in the former Soviet Union began in 1949 at the Mayak Production Association located between the cities of Chelyabinsk and Ekaterinbourg in the southern Ural mountains about 1200 km east to Moscow. During the first few years of Mayak's operation, almost 30,000 people living on the banks of the Techa River received significant internal and external exposures as a consequence of the release of large quantities of radioactive materials from Mayak. Studies of levels of radioactive contamination and health effects in this population began in the early 1950s. A systematic follow-up of a fixed cohort that includes all people who were living in Techa River villages in 1949 was begun about 30 years ago. In this paper we describe the Techa River cohort, outline the nature of the exposures and discuss the status of follow-up for the period from 1950 through 1989. While noting the limitations of the current epidemiological follow-up data, we also compare the demographic and mortality structure of the Techa River cohort with the Life Span Study cohort of Japanese atomic bomb survivors. It is seen that, despite a number of limitations, the current data suggest that the risks of mortality from leukemia and other cancers increase with increasing radiation dose in the Techa River cohort. This finding suggests that, with continued improvements in the quality of the follow-up and dosimetry, the Techa River cohort has the potential to provide quantitative estimates of the risks of chronic low-dose-rate radiation exposures for an unselected general population that will be an important complement to the estimates based on the Life Span Study that are used as the primary basis for numerical assessments of radiation risk.

Modeling the resuspension of radionuclides in Ukrainian regions impacted by Chernobyl fallout.

Following the 1986 Chernobyl event, large amounts of radioactive materials were deposited in nearby areas. Concentrations of various radionuclides were measured in air and surface soil. To study the resuspension of radioactive particulate, three different exposure situations were developed on the basis of the collected data under the auspices of the international BIOMOVS II (BIOspheric MOdel Validation Study) project. Modelers were asked to predict seasonal air concentrations and resuspension factors at several locations at different distances from Chernobyl for six successive years following the accident. Measurements of radionuclide deposition on topsoil were provided for each site along with information on soil, vegetation, land use, surface roughness, meteorology, and climate. In this paper, the three exposure situations are described, along with the initial data set provided to the modelers; two modeling approaches used to make the endpoint predictions are also presented. After the model predictions were submitted, the measured air concentrations and resuspension factors were released to the modelers. Generally, the predictions were well within an order of magnitude of the measured values. Time-dependent trends in predictions and measurements were in good agreement with one of the models, which (a) explicitly accounted for loss processes in soil and (b) used calibration to improve its predictive capabilities. Reasons for variations between predictions and measurements, suggestions for the improvement of models, and conclusions from the model validation study are presented.

Proposal of integrated test facility for in-vessel thermofluid safety of fusion reactors

A vacuum vessel (VV) of a tokamak fusion reactor like the International Thermonuclear Experimental Reactor (ITER) consists the first confinement barrier that includes the largest amount of radioactive materials such as tritium and activation products. The ingress of coolant event (ICE) is a design basis event in the ITER where water is used as the coolant. The loss of vacuum event (LOVA) is also considered as an independent design basis event. Based on the results of ICE and LOVA preliminary experiments, an integrated in-vessel thermofluid test is being planned and conceptual design of the facility is in progress. The main objectives of the integrated test are to investigate the consequences of possible interaction of the ICE and the LOVA and to validate the analytical model of thermofluid events in the VV of the fusion reactor. This paper introduces a conceptual design of the integrated test facility and a testing plan.

Overview of the Fernald Dosimetry Reconstruction Project and source term estimates for 1951-1988.

The Feed Materials Production Center, northwest of Cincinnati, processed uranium concentrates and uranium compounds recycled from other stages of nuclear weapons production, as well as some uranium ore and thorium. Particulate releases were primarily uranium (natural, depleted, and slightly enriched. In addition, two large silos containing radium-bearing residues were emission sources of radon and its decay products. The Fernald Dosimetry Reconstruction Project was undertaken to help the Centers for Disease Control and Prevention to evaluate the impact of the Feed Materials Production Center on the public from radionuclides released to the environment from 1951 through 1988. At this point in the study, the project has estimated the quantities of radioactive materials released to air, surface water, and in groundwater; developed the methodology to describe the environmental transport of the materials; developed mathematical models to calculate the resulting radiation doses; and evaluated environmental monitoring data to verify that the estimates of releases and transport are reasonable. Thorough review of historical records and extensive interaction with former and current employees and residents have been the foundation for reconstructing routine operations, documenting accidents, and evaluating unmonitored emission sources. The largest releases of uranium to air and water occurred in the 1950's and 1960's. Radon releases from the silos remained elevated through most of the 1970's. The quantity of uranium released to surface water was much less than that released to air. Best estimates of releases are reported as median values, with associated uncertainties calculated as an integral part of the estimates. Screening calculations showed that atmospheric pathways dominate the total dose from Feed Materials Production Center releases. Accordingly, the local meteorology, effluent particle size and chemical form, and wet and dry deposition, were particularly important in this study. The final goal of the project is the calculation of radiation doses to people living in the study domain, which is represented by a circle with radius of 10 km centered on the Feed Materials Production Center production area.

A Method for Evaluating the Adequacy of Workplace Air Sampling and Monitoring Locations

Abstract Current federal guidance on occupational radiation protection recognizes the importance of conducting air flow studies to assist in the placement of air sampling and monitoring equipment. In support of this, Pacific Northwest Laboratory has provided technical assistance to Westinghouse Hanford Company for the purpose of evaluating the adequacy of air sampling and monitoring locations at selected Hanford facilities. Qualitative air flow studies were performed using smoke aerosols to visually determine air movement. Three examples are provided of how air flow studies results, along with information on the purpose of the air sample being collected, were used as a guide in placing the air samplers and monitors. Preparatory steps in conducting an air flow study should include (1) identifying type of work performed in the work area, including any actual or potential release points; (2) determining the amounts of radioactive material available for release and its chemical and physical form; (3) obtainin...

Regulatory Aspects of Safe Transport of Radioactive Material in India

AbstractA large quantity of radioactive material is transported in India in various types of packages and by different modes of transport. The Competent Authority has established regulatory control at each stage to ensure basic radiation safety to transport workers, members of general public and the environment. Implementation of these regulations is carried out through design assessment, safety analysis and approval of different types of packages, inspection of consignments, checks for radiation protection measures and quality assurance. There is an emergency response system for the safe management of any transport accident. In this article the regulatory requirements for both domestic and foreign consignments are discussed. Important differences from IAEA regulations are also emphasised.

Preliminary Analysis of the Induced Structural Radioactivity Inventory of the Base-Case Aqueous Accelerator Transmutation of Waste Reactor Concept

The purpose of the Los Alamos National Laboratory Accelerator Transmutation of (Nuclear) Waste (ATW) project is the substantial reduction in volume of long-lived high-level radioactive waste of the US in a safe and energy-efficient manner. An evaluation of the ATW concept has four aspects: material balance, energy balance, performance, and cost. An evaluation of the material balance compares the amount of long-lived high-level waste transmuted with the amount and type, of waste created in the process. One component of the material balance is the activation of structural materials over the lifetime of the transmutation reactor. A preliminary radioactivity and radioactive mass balance analysis has been performed on four structure regions of the reaction chamber: the tungsten target, the lead annulus, six tubing materials carrying the actinide slurry, and five reaction vessel structural materials. The amount of radioactive material remaining after a 100-yr cooling period for the base-case ATW was found to be 338 kg of radionuclides. The bulk of this material (313 kg) was generated in the zirconium-niobium (Zr-Nb) actinide tubing material. Replacement of the Zr-Nb tubing material with one of the alternative tubing materials analyzed would significantly reduce the short- and long-term radioactive mass produced. The alternative vessel materialmore » Al-6061 alloys, Tenelon, HT-9, and 2 1/4 Cr-1 Mo and the alternative actinide tubing materials Al-6061 alloy, carbon-carbon matrix, silicon carbide, and Ti-6 Al-4 V qualify for shallow land burial. Alternative disposal options for the base-case structural material Type 304L stainless steel and the actinide tubing material Zr-Nb will need to be considered as neither qualifies for shallow land burial.« less

Regulations for the Transport of Radioactive Material in Italy: The Role of the Italian Competent Authority (ANPA)

Abstract In Italy four Ministries, Industry, Transport, Marine Merchandise and Interior, have the legal responsibility to issue and apply the transport safety regulations for radioactive material. ANPA, the National Agency for Environmental Protection, has the technical duty to issue the approval certificates and to support the various Ministries in authorising carriers for all modes of transport, in updating the regulations and advising in the case of emergency conditions. ANP A is monitoring the quantity of radioactive material transported in Italy, the radiation doses of workers and public. and verifying the implementation of transport regulations through inspections of the carriers and during storage in transit and handling.

Differences in the synthesis of total and poly(A)<sup>+</sup>RNA in the Kennebec potato and its dihaploid

RNA synthesis as measured by the incorporation of tritiated uridine into trichloroacetic acid insoluble material was studied in the leaf protoplasts of cv. Kennebec and its parthenogenically derived dihaploid. Protoplasts of cv. Kennebec incorporated tritiated uridine at a greater rate and accumulated more than twice the amount of radioactive materials than did the dihaploid over a 6-h incubation period. Poly(A)+RNA, isolated from the total RNA of the tetraploid and of the dihaploid, by oligo(dT)-cellulose column chromatography, was present in amounts of 11.3 and 5.2 % respectively. The tetraploid synthesized 4.8 times the amount of poly(A)+RNA that was synthesized by the dihaploid.

Assay of uranium in crude diuranate cakes and MgF2 slag produced at the natural uranium conversion plants by γ-ray spectrometry

A transmission-corrected γ-ray counting method has been employed for the assay of uranium in crude Na2U2O7 cakes produced at the Uranium Conversion Facilities. A 3″×3″ NaI(TI) detector was used in conjunction with a 400-channel analyzer. The observed count rate of the 1 MeV γ-ray emitted by the238U in the sample was corrected for sample self-attenuation, measured with a65Zn (γ-energy ∼1115 keV) transmission source. A calibration factor determined by measuring a standard of known amount of radioactive material in the same form and geometry as the unknown sample was used to convert the transmission corrected count rate to the amount of uranium in the weighted sample. Another γ-spectrometric method is described for the assay of the U-content in the MgF2 slag produced during the magnesiothermic reduction of UF4 to U-metal ingots at the natural U-conversion plant.

A Task Analytic Investigation of Safety in Industrial Radiography

Industrial radiography is a commonly used method of inspecting materials for flaws. These inspections use small but significant quantities of radioactive material to penetrate the inspected object and expose corresponding radiographic film. The film is then examined to determine if there are any indications of flaws in the inspected material. Failure to perform industrial radiography properly can result in serious injury due to radiation exposure. An examination of accident reports and annual radiation dose rates for industrial radiographers suggests safety in this field is an important concern. This paper describes how an observation-based, two-part, task analysis was developed and conducted for this potentially hazardous process.

Calculation of Individual Dose Equivalents on the Territory of Eastern Slovakia after the Chernobyl Accident

The accident in the nuclear power plant at Chernobyl in the USSR resulted in the release of substantial quantities of radioactive material and remarkable increases in radioactivity in the environment in many European countries. For an estimation of the accident consequences to population both the individual and the collective dose equivalents must be calculated. This paper deals with the calculation of the individual dose equivalents to persons living in the territory of eastern Slovakia. The calculation is based on real activity concentration measurements of environmental samples. For children the value of the total committed effective dose equivalent was calculated as 1.20 mSv, for adults it was 0.31 mSv

Multiple successive immunoprinting: A fast blotting technique of a single agarose isoelectric focusing gel

Multiple successive pressure blottings of a single agarose isoelectric focusing gel were performed on normal and CNBr-activated nitrocellulose (NC) filters. The results obtained by multiple successive 10s immunoprints were compared to those obtained by a single 10 min immunoprint. To quantify the transfer efficiency of these techniques, a defined amount of radioactive material was separated by isoelectric focusing on agarose gel. After separation and pressure blottings of the gel the NC filters were submitted to autoradiography. The amount of radioactive material bound to the NC filters was determined by scintillation technique. The single 10 min pressure blot was more efficient than each of the multiple successive 10s prints. However, the latter procedure allowed equal resolution and resulted in a higher recovery of total radioactivity than the single immunoprint technique. The aim of this paper is to show how to obtain highly reproducible prints of electrophoretic patterns in an agarose gel of heterogeneous samples when accurate multiple immunodetections are to be performed. This technique was tested to characterize the grass pollen specific immunoglobulin classes and subclasses from an allergic patient.

Three Mile Island Unit 2 Reactor Building Basement Concrete Activity Distribution

Sample and measurement data used to determine the quantity of radioactive material in the concrete walls and floor of the Three Mile Island Unit 2 (TMI-2) reactor building (RB) basement are given. ...

Fucosylated glycoconjugates in mouse preimplantation embryos.

Preimplantation mouse embryos were metabolically labelled with 3H or 14C-fucose to investigate the synthesis of fucosylated macromolecules. Scintillation counting revealed that there was a progressive increase in both total fucose taken up by the embryo and incorporation of fucose into TCA-precipitable material as embryos developed from the 4-cell to the blastocyst stage. This was reflected in the increasing intensity of bands on autoradiographs of radioactive fucose labelled proteins separated on 10% SDS-PAGs between the 4-cell embryo (at which stage bands were first detectable) and the blastocyst. Minor qualitative changes in fucoproteins were detected at the time of compaction and additional bands appeared at the blastocyst stage. Preliminary analysis of fucolipids in 6- to 8-cell embryos indicated that an approximately equal amount of fucose was incorporated into lipid and protein. Autoradiographs of semi-thin sections of 3H-fucose-labelled embryos showed substantial amounts of radioactive material in the vicinity of the plasma membrane both adjacent to other cells and facing the zona pellucida. These data would support a predominant role for fucoconjugates in cell surface events in the preimplantation embryo from the 8-cell stage.

Nuclear Power and Technological Authoritarianism

When the lid blew off the Chernobyl No. 4 nuclear reactor on April 26, 1986, it released the largest quantity of radioactive material ever in one technological accident. The estimated 28 megacuries of escaping gases dwarfed the less than one megacurie released in the 1957 Windscale (U.K.) accident and the 17 curies from t.he l 979 Three Mi le Island (U.S.) accident. One hundred thirty-thousand people within a 30 kilometer radius were evacuated, and 300-400 million people in l.') nations were put at risk of radiation exposure. Present forecasts of additional cancer deaths attributable to the Chernobyl accident range from 5,000 to 75.000 (Byrne and Rich, 1987: 4).

A preliminary assessment of the consequences for inhabitants of the UK of the Chernobyl accident.

The accident with the nuclear power reactor at Chernobyl in the USSR resulted in the release of substantial quantities of radioactive material and subsequent increases in radioactivity in the environment in many countries. In this paper the situation in the UK is considered and, from the preliminary monitoring measurements, the major routes of exposure of the population are identified and quantified. For the most part exposures in the UK are within variations in levels of natural background radiation to be found in Europe. An exception is the dose likely to have been received by the thyroids of young people in the north of the UK. From reported measurements of I-131 in milk it is predicted that thyroid doses up to 10-20 times the annual doses received from 'normal' natural background radiation might have affected young children drinking fresh cows' milk. The ways in which this component of exposure could have been reduced and the criteria that govern decisions as to whether or not to implement counter-measures are discussed. The importance of I-131 in milk as a route of exposure of the population to radioactivity is a feature that the Chernobyl accident has in common with the Windscale accident in the UK in 1957, and underlines the importance of milk-producing regions in relation to reactor-sitting policy.

Influence of phenobarbital and TCDD on the hepatic metabolism of TCDD in the dog

The influence of phenobarbital and TCDD pretreatment on the formation and biliary excretion of TCDD-metabolites following single doses of 3H-TCDD was investigated. Without pretreatment, 24.5% of the absorbed 3H-TCDD dose was excreted in the bile within 110 h. Phenobarbital did not influence this rate, whereas a single dose of 10 micrograms of unlabeled TCDD/kg b.wt nine days earlier resulted in a doubling of the amount of radioactive material eliminated in the bile (47.4%).